Pneumatic-dispatch apparatus



Feb. 28,y 192s.

E. BACKHOUSE PNEUMATIC DISPATCH APPARATUS Filed Feb. 24, 1927 6 Sheets-Sheet 1 \N\\\ \\\\\\\\\\\\N\ \\B 6 Sheets-Shed. 2

Filed Feb. 24, 1927 E BACKHOUSE PNEUMATI C DI S PATCH APPARATUS Feb. 28, 1928.

Feb. 2s, 192s. 1,661,027

E. BAcKHoUsE PNEUMATIC DISPATCH APPARATUS Filed Feb. 24. 1927 6 Sheets-Sheet 3 Feb. 28, 1928.

E. BAcKHousE PNEUMATI C DI SPATCH APPARATUS Filed Feb. 24, 1927 6 Sheets-Sheet 4 Feb. L28, 1928; 1,661,027

E.BACKHOUSE "PNEUMATIC DISPATCH APPARATUS Filed Feb, 24, 1927 -6 Sheets-Sheet 5 Feb. 28, 1928.

E. BAcKHoU sE PNEUMATIC DISPATCH APARATUS Filed'fFb. 24. 192'7 6 Sheets-Sheet G Patented Feb. 28, Y1928.

UNITED STATES- EDWARD 4BACKIIOUSEy 1 PATENT OFFICE.A

F LONDON, ENGLAND.

PNEUMATZIG-DISPATCH APPARATUS Application mea February 24, 1927, serial No.

are conveyed pneumatically and discharged 5 at the desired substationarand particularly such systems as are provided with mea-ns whereby, during `the periods in which the transmissions are not being effected, the flow of air through the system. is automatically A reduced or stopped by devices controlled byl timing mechanism, and the present invention has for its ob]ect `to provide pneumatic dispatch apparatus of high efficiency andf simple construction,

Heretofore attempts havebeen ,made to effect the same object by intricate mechanical or electrical mechanism, but such mech-` anism has been found to be liable to get out i of order, and the present invention provides means for effecting i the same general ob-` "ject in a greatly simplified manner, with the avoidance of unnecessary levers and catches.

In one of these previously proposed devices, in order to automatically apply power cut off the power when a carrier'is ejected, the transmission tube is connected to vacuum by a balanced valve controlled by pressure changes in the line acting on a flexif` "0 ble diaphragm, there being also providedan auxiliary Vdiaphragm or valve'open jat one side to atmosphere and at `the other to the The present invention l comprises pneu-1 matic dispatch apparatus having automatic controlling apparatus, characterizedy by such apparatus having pneumatically f opera-ted controlling devices arranged in aivalve con`` trolled inlet to the system. ,The pneumatically controlled devices may be arranged in A Ul an inlet tothe system separate from that through Which the dispatch carriers are inserted.` i `The valve-controlled inlet is opened when the vacuum in the system is broken as b the insertion of a carrier through` a dispatc iorifice, and is closed again after a predetermined intervalby timedwmechanism.

In a. conveying syste-m to which this in-A When a carrier is inserted and to rapidly A170,674, fand in Great Britain February 1, 1926.

vention is particularly applicable, each tube is 1n the torni of a loop running from a central station to a sub-station and back again,

directions simultaneously. The several tubes are usually connected in parallel at the central station to the exhausting apparatus. f

Various embodinients of the `invention are illustrated by the accompanying` drawings, Vwherein A Figure l is a partly sectional front elevation, i

Figure 2 a side elevation, and

Figures 3 and l sectional and outside plan views oi one modification of a valve inlet made in accordance with the present invention.

Figure 5 is a front elevation,

Figure 6 a side elevation and y Figure 7 a plan of a detailof the apparatus for applying the invention to a double tube system, While a further modifica tion of a valved inlet is illustrated in section in Figure'9, Figure 10 being a sectional plan through Bu of Figure 9, and Figso that transmissions can be made in both ure 11 a sectional plan through A-A of Figure 8. y y i In the construction of the apparatus illus- Ltrated a carrier inlet 2 as arranged at a central position is provided With a spring `controlled or counterpoised door 3, the carr, rier being drawn through the tube in the usual manner by `an induced current of air produced by an exhauster arranged at the opposite end vof the loop. Adjacent the lll) door covered inlet 2 of a dispatch tube 4is l fixed a controlling cylinder 5 provided at its lower end with a controlling valve 6 arrangedlto be opened 'by gravity and above which is a lateral opening `7 communicating by means of a port-9 with the dispatch tube 4 immediately above its door 3, so that after a carrier has beeninserted in the dis i patch tube 4, and its door 3 closed, air is` drawninto thetube through passage-8 of thecontrolling valve 6 andthe communi eating passage 7 after the controllingvalve (3 has been opened due to the vacuum in the system being destroyed by the opening of i a dispat-chdoor such as 3. for the purpose of inserting a carrier in the tube4. controlling valve 6 is raised to its seating automatically after a ipredeterminedv inter" val, and is held againstits seating by` atinoa` pheric pressure as llong as the tube 4 is un- The Y der vacuum. Vhen a door such as 3 at a dispatch aperture is opened to insert a carrier either at a sub-station some distance along the tube or at the central station, the vacuum is brolren and the control valve 6 falls, thus permitting a iiow of air through the system.

In the lower portion of the control cylinder below the communicating passage 7 to the dispatch tube 4 is mounted a light disc 10 formed on the lower end of a sleeve valve 11 sliding on a. tube 12 iixed axially in the control cylinder and provided with ports 13 which are covered by the sleeve 11 when the sleeve is raised. The said ports forni a means oi! con'n'minication between the atmospheric or internal air pressure in the system,y and the upper side of an annular piston 14 sliding in the control cylinder 5 and on the central tube 12 therein. l Suitable apertures 15 are provided in the upper portion of the central tube 12 so as to place it in communication with the cylinder 5 above the annulaipiston 14.

In a cover 16 of the control cylinder is provided a valve 17 adjustable from outside the cylinder and controlling a passage 18 between the upper portion of the cylinder 5 and a suction or vacuum pipe 19, which pipe may be constructed as a supporting member of the apparatus. When the sleeve valve 11 at the lower portion of the control cylinder 5 is raised over the ports 13 in the central tube, the air is slowly extracted troniV the cylinder 5 and the annular piston v14 is raised at a rate corresponding` to the setting ci' the adjustable valve 17. The time for this operation is adjusted to suit the transit time of the carrier in the tube in use. When the annular piston 14 nears the top of its stroke it engages with a cross member 20 extending through slots 21 in the central tube 12 and to which cross mein-r ber 2O is fixed the upper end of arod 21 passing through the central tube 12 and carrying at its lower end the valve 6 at the lower end of the control cylinder 5, and so cause the iiow ol air into the control cylinder 5 to cease and leave the sleeve valve 11 free to fall into the open position by gravity. The air pressure above and below the annular piston 14 is now equalized and the piston 14 falls to its lowest position in readiness for another transmission.

purpose of making a transmission, due to the tact that the flow of air is interrupted, and owing to the dropping of the sleeve valve air is allowed to flow through the central tube to the top of the annular piston, which then falls to its original starting position.

Whilst it is essential that the resetting of the timing mechanism should take place on the insertion of each carrier in the tube, it is not desirable that this should be lbrought about by the discharge of the carriers at the terminal points, such dischargecausing a momentary interruption in the flow of air through the system. It has been ascertained that this discharge occupies a period of about half a second, whereas the insertion of a carrier cannot be accomplished in less than double this period. In the present invention therefore means arel provided to prevent the sleeve valve 11 from falling during the period occupied by the discharge setting to be accomplished. The delay of' falling of the sleeve valve may be effected by any suitable apparatus such as by providing above the sleeve and rlined on' the `central tube an inverted dash pot in which some what wclosely its a disc 31 iXed'on the upper end of the sleeve valve 11.r Y

In the case of pneumatic tubes of considerable length or where longer time intervals are required-and they cannot be conveniently obtained by the movement ol' the annular piston 14 alone, the time interval may be further extended by an auxiliary piston such as 40 Figure 8 working in an oil dash pot 41, or similar device, and this device may be attached to 'the lower end of the control cylinder valve rod 21. y

The apparatus so far described is suitable for controlling lines 'of pneumatic tubing singly, but it is sometimesdesired to link up two or moretubes such as and 51 Figure 5, provision being made to admit air to Jthe tubeit is desired to use. In such a sys temitis proposed to use'the same timing device to control more than 'one tube. Y In the Case Vof a. pair of tubes 50 and 51 this may be effected by connecting the open end or the control cylinder to the-tubes by means of a two-way box 53 "on theunderside of which are arranged side by side the apertures lor dispatching thejcarriers through f either of the tubes each being closed by a hinged door 61, 6b. Inside the box are provided ports 52 and 53 connecting the two tubes 50 and 51 with the air supply.' A

swing iiap valve 54 is arranged for closing either one or other of these ports, andthis valve 54 is operated by a vertical spindle 55 y provided with a forked lever 56 which actuated by projections 57", 57b on the hinged plunger 58 operating a crankpin 59 is artube 51, and viceversa when the right hand door 6b is opened. A. spring-controlled ranged to give the fiap valve 54 a bias towards either side of a central line, so that it will remain on its seat when thrown over.

. rlhus when the dispatch door for either' tube is opened, the air admitting or control valve 6, see Figures 1 and 2, at the lower end of the control cylinder 5 is opened, andthe air supply connected to the tube in use.

The modiiication illustrated by Figures 8 and 11 is for control apparatus requiring larger time intervals than for which the above apparatus is intended.

In this modification an oil dashpot 41 is attached to thelower end ofthe mechanism. The rate of movement of the main piston 14 is determined by the setting of a screwdown valve 60in the piston 40 of the oil dashpot 41.

In this modification the inlet valve 17 shown in Figure 1 in the cylinder head 16 `is not necessary, and as will be seen a simple connection is made to the suction pipe 62 above by a port 63 in the `cylinder cap 64;

The cylinder cap` 64 is provided with a` bracket portion 65 which is secured by a bearing member 66 and screws 67 to the pipe 62.

They method of operation is substantially the same as outlined `in the previous modilication and corresponding parts are given the same referencenumerals. Assumingthat` no transmissions are being made in the pneumatic tube system, and the `predetermined time intervals` have elapsed, then the `valve 6 will have been raised to this seat, and held system being under vacuum. Directly a dispatch aperture is opened at anypoint on the side of the main piston 14.` As soon as thisV has been done, an upward force is exerted on the said piston, owing to the vacuum created above.

In the mechanism of the dash pot 41 aA hook 70 on the lower end of the piston rod 21 however, is in engagement with a catch 71 on the oil. dashpot piston 40 and the latter can only be raised at the rate permitted` by the flow of oil through the adjustable valve 60 to the lower end of the piston 40. After a predetermined interval of time, the

will fall to the originalposition in piston 40 will have been raisedto a point where an extension 72 of the catch 71 engages with ya fixed pointrepresented the step 74 on the downward projected pin 73.

The hook 70 isby this means released just as across'pin 75 reaches a sleeve 76 forming `part of the main valve (i, and the latteris suddenly lifted to `its seat.`

` In consequence of this,\the sleeve valve 11 now falls to its lowest position, uncovering the ports 13 `and establishing a state ot equilibrium in the conditions above and below the main piston 14.` The latter is theretore deprived of its support, and`together with the piston 40 in the oil dashpot 41, readiness ior a further transmission.

The resetting on the introduction ot a subsequent carrier before the preceding one has reached its destination, is accomplished in precisely the same manner to that previously described. It should be noted that as the piston40 in the oildashpot 41`fa1ls by gravity, the oilis allowed to How from the lower side tothe upper side through the mushroom valve 77.

Referring to piston 14 it will be noted that this is of the plain type and the portion 78 shown on thev drawing represents a oating annular ring composed of compressed felt or other suitable material. A projecting pin 79 `onthe lower side of the piston 14 engages with a stationary fork 8O so as to prevent the hook 70 from turning out of in Figure 1 as associated with the sleeve valve 11 has not been shown in Figure 8 but it is desired to retain the use of this feature when required `with, the modiication shown in Figure 8. M

What I claim and desire to secure by Letters Patent is there by atmospheric pressure-the whole 1. A pneumatic dispatch apparatus of the kind vspecified having pneuma-tically operated controlling devices arranged in a valve controlled inlet to the system, a gravity opened valve arranged to close the inlet of said valve controlled inlet to rthe system, a timing piston, an oil dash pot to which said piston is connected; said 'dash pot being arranged concentrically thereto, said piston having a spindle which passes freely through said gravityopened valve.

2. A pneumatic dispatch apparatus having automatic controlling apparatus in an air inlet to the system separate from the carrier inlet, a gravity opened valve, a disc `movable freely inthe air inlet passage by the suction of the system, timing mechanism for closing the valve having a piston operated by vacuum tank pressure, and means for placing the upper and lower sides of the piston in communication with oneanother, the gravity valve being arranged to close the separate air inlet completely and toy be iso opened and held open by gravity when both sides of the piston are placed in communication With one another, the disc operating the means'for placing both sides of the piston in communication with one another.

3. A pneumatic dispatch apparatus having automatic controlling apparatus in an air inlet to the system .separate from the carrier inlet, a gravity opened valve, a disc movable freely in the air inlet passage by the suction of the system, timing mechanism for closing the valve having a piston operated by vacuum tank pressure, and means for placing the upper and lower sides of the piston in con'imunication with one another', the gravity valve being arranged to close the separate air inlet completely and `to be opened and held open by gravity when both sides of the piston are placed in communication with one another, the disc being operatively fixed to the means for controlling the passage placing the two sides of the pieton in communication with one another.

4. A pneumatic dispatch apparatus having automatic controlling apparatus in an air inlet to the system separate from the carrier inlet, a gravity operated valve, and timing mechanism for closing the same operated by the suction of the system, means for rendering the timing mechanism inoperative and dash pot mechanism for controlling the same, the gravity valve being arranged to close the separate air inlet com-4 pletely, and open by gravity When the dash pot has operated to render the timing mechanism inoperative.

5. A pneumatic dispatch apparatus hav-` ing automatic controlling apparatus in an air inlet to thesystem separate from the carrier inlet, a gravity operated valve, and timing mechanism operated by a piston subjected to vacuum tank pressure through a4 regulatable opening, means for connecting the piston with the valve, the valve being arranged concentrically with the piston and the rod is provided at its lower end with a Y hook, an oil dash pot having a. piston provided With a pivoted, catclna catch releasing` projection being provided in the oil dash' pot, the pivoted catch being arranged to engage the hool; on the rod of the timing piston and to be disengaged therefrom when a projection of the catch engages the releasing projection. Y

7. A pneumatic dispatch apparatus having automatic controlling apparatus in an air inlet to the system separate from the 'carrier inlet, an air inlet valve closed by a cylinder and piston timing apparatus of Which the rod is provided at its lower end With a hool-r, an oil dash pot having a` piston provided with a pivoted catch, a catch releasing r jection being provided in the oil dash pot, and a rod depending from the timing piston, and a fork fixed in the cylinder of the timing apparatus, the hook beingr held in the path of the catch by the rod depending from the timing piston passing through the fixed forks so that the pivoted catch will engage the hook on therod of the timing piston, and be disengaged therefrom when a projection ofthe catchengages itsreleasing projection.

In witness whereof I Vaffix my signaturef` y EDWARD `BacinioUsii. 

